Here's another picture of the whole tree

{{gwi:106579}}

I have been growing apple trees for only a few years but my guess is your tree hasn't much more time on the planet.Looks like a bug hole on the bottom part. And disease will get in there. And the tree just will have no way of healing that big of a loss of bark. I don't know if you got some sunscald or a pest nibbled on the bark.

The bark and cambium layer are missing. Maybe voles or maybe s weedeater attacked it. If it does live it will always be a weak tree, I would start over, preferably not with a "cocktail" tree. Al

I saw some teeth marks that make the indentation in the woods. poss voles or rabbits. If you decide to get a new tree make sure you protect with some type of bark guard( sump pump hose etc.). If you know how to graft than I would cut the tree to the ground level and let some new shoots to start this summer and re-graft next april with the variety you like. You can learn how to bark graft on you tube. Good Luck,

Tony

Looks like impending death to me. Some combination of rodent damage plus fireblight or canker. I would agree that it *might* be worth a shot cutting it off at ground level and grafting over in future years, if it will even survive such a thing, which is doubtful. It's too bad, especially on a 4-in-1 -- I feel bad to say it, but it looks like this tree simply is not going to make it. In future, you'll want to protect your tree from varmints and also spray against fireblight or whatever it might be that people believe has affected the tree.

I don't know where you live but a multi grafted espalier apple tree would fit in nicely there. Check out your local nurseries.Some do carry them allready growing well. But before you do that if you don't know much about apple growing. Rip out that tree and start now reading past posts on growing and caring for apple trees. This is a great place to read plenty of old posts about growing apple trees. Then by next spring you will be prepared to grow again. My espalier I bought at a local nursery has four different apples on it and fits snugly in a small area of my veg garden.

That looks like dead tree disease.
LOL

Thank you so much for all your input!! I guess I should start looking for a new tree.

I'm trying to learn something from this. Is there anything I could have done should I spotted this earlier? I'm also having a Jujubee tree that loses some barks near the ground. Its trunk has always been rough and dry though, and it is living strong.